1. Field of the Invention
The present invention relates to electrosurgical hand controlled and foot controlled pencils. More specifically, the present invention relates to an electrosurgical pencil having a flexible, substantially solid pencil housing.
2. Prior Art
In electrosurgical techniques using electrosurgical pencils, an electrosurgical generator generates current in a particular wave form upon demand, and the current is carried to an electrosurgical pencil having a relatively small blade. The current is transmitted through the blade to the patient and back to the generator through a ground plate attached to the patient. Since the blade is relatively small relative to the ground plate, the energy being transferred to the patient through the small blade is concentrated such that the high frequency causes tissue destruction. Typically, such devices have two modes of operation, cutting and coagulation, which require current having different wave forms.
In hand controlled electrosurgical pencils, an internal switch, usually a printed circuit board, is incorporated into the pencil housing. The housing additionally includes appropriate buttons to select the desired mode of operation through the printed circuit board (i.e., either a cutting or coagulation signal). In electrosurgical pencils without hand actuations, often called foot controlled pencils, an actuation switch is positioned remote from the pencil housing to be controlled by another manner such as by the operator""s foot.
In both the hand controlled and foot controlled electrosurgical pencils, the pencil housing is intended to form a barrier to prevent fluid entry therein. The pencil housings of the prior art are generally formed of two hollow, rigid plastic parts that are joined together by ultrasonic welding. The hollow configuration, ultrasonic welding and the rigid construction of the prior art pencils all provide for a series of problems. The use of an ultrasonic assembly for ultrasonic welding may still leave voids between the two housing parts and compromise the hermetic seal provided. Additionally, the rigid plastic housing does not provide any stress relief for the cable which connects the pencil housing to the electrosurgical generator. Consequently, the rigid plastic housings increase the likelihood of a break in the cable (i.e., wire fatigue) at the point where the cable enters the pencil housing. A further problem with the prior art housings is that they do not accommodate changes in the blade positioning. For example, users sometimes bend the blade of the blade electrode to more effectively reach the operating position. However, the bending of the blade itself is undesirable since the blade can reach relatively high temperatures, and touching the blade itself can be dangerous to the user and may contaminate the electrosurgical pencil.
An object of the present invention is to overcome the drawbacks of the prior art electrosurgical pencils. A further object of the present invention is to provide an electrosurgical pencil providing a substantially electrically insulated housing hermetically sealing the interior to provide a more effective insulated barrier to the external environment. A further object of the present invention is to provide an electrosurgical pencil which can be easily manipulated to the desired operating configuration. A further object of the present invention is to provide an electrosurgical pencil which is efficient and economic to manufacture.
Many of the objects of the present invention are achieved by providing an electrosurgical pencil for delivering high frequency cutting and coagulation signals from an electrosurgical generator with the pencil including a flexible, elongated pencil housing having a cable receiving end and a blade electrode receiving end opposed from the cable receiving end. The pencil housing is provided with a mechanism for permitting bending of the pencil housing between the cable receiving end and the blade electrode receiving end. Further objects of the present invention are achieved by providing that the housing is formed of an elastomeric polymer which is sealed around a portion of the collet and around a portion of the cable forming a substantially solid housing therebetween.
The present invention additionally discloses a method for manufacturing an electrosurgical pencil to achieve the above objects. The method according to the present invention includes the steps of encapsulating the elongated elastomeric pencil housing around a portion of the cable and around a portion of the collet to form the substantially solid housing therebetween. The electrically insulated solid housing substantially completely encapsulates the interior mechanisms of the electrosurgical pencil, thereby creating a hermetic seal and offering a seamless, insulated barrier to the external environment. An insert molding process provides for an efficient and effective method for manufacturing the electrosurgical pencil of the present design.
In one embodiment of the present invention, the mechanism for permitting bending includes a plurality of parallel grooves on opposite sides of the pencil housing. One embodiment of the present invention additionally includes a metal collet positioned within the pencil housing wherein the metal collet is bendable with the pencil housing and the metal collet maintains a bent position of the pencil housing. The metal collet may include a bendable flat portion with a round electrode receiving socket attached to the flat portion for rotatably receiving a blade electrode therein through a blade electrode receiving end of the pencil housing. The pencil housing may be hermetically sealed around a flat portion of the metal collet.
A hand controlled embodiment of the present invention provides a manually actuated switch embedded within the pencil housing between the collet and the cable with both the collet and the cable attached to the switch. The switch may have a rigid switch body to provide rigidity to the elastomeric pencil housing of the electrosurgical pencil. The rigid switch body may be spaced from the cable receiving end of the pencil housing wherein the pencil housing tapers from the end of the switch body to the cable receiving end. Additionally, at least one button may be provided on the pencil housing with each button overlaying a depressible activation member on the switch wherein the housing includes an encapsulating membrane over the activation member between the button and the activation member.
These and other objects of the present invention will be clarified in the description of the preferred embodiment wherein like reference numerals represent like characters throughout.